Various exercising devices exist for permitting a user to do different types of exercises in different body positions to strengthen corresponding muscles. Such devices, however, are generally limited in the number of different exercises which could be effectively done thereon. It would be desirable to provide an exercising device which is versatile enough to permit the selective performance of a number of different exercises and with some therapeutic purpose rather than just creating body-strength and body-bulk. Since most devices strengthen muscle regions such as the arms, legs, chest, stomach, etc., regions, which for the most part with normal everyday usage are not readily susceptible to injury. Yet, one muscle group which is frequently injured with normal use, is the lower back or lumbar region. However, to strengthen this region one must do a variety of exercises circumferencing the lower trunk. These exercises which include sit-ups, back extensions and lateral extensions should be done as a group exercise to acquire the best results. The first circumference exercise, sit-ups, are frequently used to strengthen the abdominal muscles. While performing sit-ups, the user simply lies on his back and bends forward. The second exercise is the back extension where the user lays on his stomach and flexes the trunk downward and extends the trunk upward. This exercise specifically isolates the spinae erector muscles. The third, most unique, and most neglected exercise to prevent severe lower back strain is lateral extension which exercises congruently and simultaneously the abdominal oblique and quadratus lumborum muscles. The quadratus lumborum muscles are responsible for lateral movements of the trunk and are probably the most susceptible muscles to lower back injury or lower back strain. The abdominal oblique muscles compress the abdominal wall preventing protrusion and lordorsis of the abdomen.
It would be desirable to have an apparatus enabling one to do the lateral extension exercise allowing one to isolate the abdominal oblique and quadratus lumborum muscles which play in intricate role in the extension of the trunk from the flex position (i.e., straightening up after touching one's toes). This extension movement, however, actually employs a circumference of the lower trunk muscles, for example: the abdominal rectus formed anteriorally to the stomach and intestinal region; the spinae erector running vertically along the vertebral column; the abdominal oblique found laterally or rather on both sides of the individual, attached to the top of the pelvis (iliac), and to the lower rib cage; and the quadratus lumborum found in the immediate lower back on either side of the spinal column attaching to the last rib, lumborum vertebrae and pelvic crest, yet positioned more laterally than the spinae erector.
There are three primary reasons why one encounters lower back muscle strain. The first reason is the individual's neglect and ignorance of the abdominal oblique muscles allowing atrophy of this muscle group therefore losing their ability to contract and compress the abdominal wall. The second reason, which coincides with the first, is the increased elasticity of the abdominal rectus, due to a number of years of poor posture by the individual expecially while sitting. What occurs is that the individual slumps, relaxing the lower back and abdominal rectus muscles causing protrusion of the abdominal wall and increasing elasticity of the rectus muscles. As the abdominal rectus muscles become more elastic, they lose their force of contraction and yield a greater load upon the remaining three muscle groups, (spinae erector, abdominal oblique, and quadratus lumborum), during extension of the trunk. The third reason why one encounters lower back problems is simply that the individual is taught not to use this region in exercise, especially in strength development type work. Consequently, this area becomes weak from lack of a strong stimulus and lack of a high chemical metabolic activity within these muscle fibers. Furthermore, when the individual does use this region in some flexion and extension movement, he frequently uses poor body mechanics. For example, one may bend over to pick something up which is not directly in front of him (picking up a grocery bag from the seat of a car) and therefore may turn slightly (lateral movement) to accommodate this position. One would then apply the load to one quadratus lumbordum muscle and forward toward the oblique muscles. These areas not properly conditioned, cannot sustain the load, and therefore may encounter what is thought to be "contraction" of the muscle fibers, a state which the muscle fibers become fully contracted and will not relax; sometimes causing inflammation and prostaglandin synthesis, mediating pain.
Therefore, by acquiring a device with the versatility to accommodate all of these exercises, while at the same time accommodating individuals of different physical sizes, one may help prevent lower back strain by isolating, stimulating and conditioning the certain muscle groups which yield the the forces of contraction necessary to sustain a given load during extension of the trunk.